1. Field of the Invention
The present disclosure relates to a vehicle lamp unit which is used in a so-called projector-type vehicle lamp.
2. Related Art
Among vehicle lamps, such as a head lamp, a so-called projector-type vehicle lamp is known as one of various types of vehicle lamps. In the projector-type vehicle lamp, light emitted from a light source disposed on an optical axis is collected and reflected by a reflector in a forward direction toward the optical axis and the reflected light is irradiated to a region in front of the lamp via a projection lens provided in front of the reflector.
In the projector-type vehicle lamp unit, a discharge light emitting portion of a discharge bulb, a filament of a halogen lamp, or the like is used as the light source. However, because the light source is a line light source having a certain size, the reflector is also required to have a certain size. For this reason, it is difficult to remarkably decrease the size of the lamp unit. Therefore, for example, JP-A-2003-317513 discloses a semiconductor light emitting element (LED), which corresponds to a small light source, used as a light source unit for the vehicle lamp.
In the light source unit disclosed in JP-A-2003-317513, because the reflector is formed such that a distance between the semiconductor light emitting element and the reflection surface in a given direction (a given direction substantially perpendicular to the optical axis) is set to about 10 millimeters (mm), a remarkably further decrease in the size of the lamp cannot be achieved.